One million flights not one million miles of travel. There'd be a lot of dead frequent fliers if it was a death per million miles.

Yes it will be likely needing a 99.99%+ accuracy. I just made a vague suggestion, as I didn't have time to look it up. Elon mentioned it too, it doesn't just need to better than a human, but massively better. I don't know the exact accident stats for human drivers. But self-driving cars will need to be much higher.